There are many reasons why it is undesirable to have inadvertent disconnection of a plug-socket type electrical connection. The conventional two-pronged and three-pronged plug and socket type electrical connection is ubiquitous in household and industrial electrical distribution systems and in power cords used for myriad purposes. Unwanted removal of a plug from a socket type connector is at least inconvenient, can result in economic loss due to damage to computers, power tools, failure of heating and refrigeration systems and many, many other applications of electrical power. Still further, the risk of exposure of a live electrical socket connector element to unwanted insertion of conductor means or contact with humans can be injurious, if not fatal.
Accordingly, there has been a long felt need to provide suitable means for preventing unwanted disconnection of plug-socket type electrical connectors and to prevent the removal of isolator or socket cover devices to minimize the risk of persons, such as small children and infants, coming into contact with the socket connector elements.
Various devices have been developed for preventing the removal of a plug from a socket type connector element. It has been suggested to provide mechanism which includes a pin insertable through the socket contactor element and through conventional holes or openings formed in the prongs of conventional plug members. Prior art devices are relatively complicated and, generally, are not adapted for use with recessed socket type connectors typically mounted in a building wall or other structures so that the socket member is substantially co-planar with the wall surface. Certain devices have been developed to overcome this deficiency included a device which includes a relatively complicated mechanical linkage which is mounted on and within a recessed wall type socket enclosure. Alternatively, add on type socket connectors including multiple pairs of socket contactors have been developed which include relatively complicated combinations of switch and locking pin members which are insertable through the prongs of the plug member when it is engaged with the socket contactors to lock the connector in assembly.
Still further, there have been efforts to develop locking devices for power cord connections of the plug-in socket type, which devices are also relatively complicated and are not easily retrofitted to existing power cords.
The present invention overcomes some of the deficiencies of existing locking devices for plug and socket type connectors, as will be appreciated by those skilled in the art from reading the following summary, detailed description and claims.